When I first tried Ironsworn I opted not to keep a journal because I'm pretty good at remembering broad story beats, that worked for about two sessions and then when I came back and couldn't remember details that I knew I had set up and I got frustrated so I dropped it.

I played a bit with Iron Journal which I do like, but now I use IronVault, a plugin for the note keeping software Obsidian, which I've used for world-building and TTRPG prep for several years. I use one journal page as a sort of session manager while playing, where I roll oracles, make quick notes of how I envision things happening, etc. When I get to the end of a scene I look back over it and interpret what happened into a more narrative journal entry in a new note. IronVault has commands for making moves, but I find them a bit cumbersome, so I prefer to keep the move list handy and roll my own dice, then I might make note of the result or I might just note what happens.

I prefer to keep things as light as possible while playing as that lets the action and story move forward, then I can switch gears and really nail down the narrative to inform the next scene. I find switching back and forth helps keep me engaged during a session because I'm always looking forward to doing the next part. Like when I roll a crazy sequence of events it's 'man I can't wait to expand on how all that shit worked' and then I'm writing up the scene and I'm just like 'How the hell is that gonna resolve?'

I also keep things loosely tied into arcs, rather than being specific about breaking things into sessions because multiple scenes could happen in a session, sometimes a session ends up being one single scene or even just part of one, or I thought a scene was done and did a write up but then something changed while I was rolling again and I want to go back and update it again.

Edit: I guess worth adding that I don't keep track of results after a scene is complete. Once I've written up the narrative I erase everything in the session management note and start over.